The present invention relates to a substituted phenyl(or pyridyl)urea compound and a herbicidal composition containing the substituted phenyl(or pyridyl)urea compound as an active ingredient.
More particularly, the present invention relates to a compound represented by the following general formula (I): ##STR2## wherein A represents an alkylene group; B represents a nitrogen atom or CH; R represents a hydrogen atom, a lower alkyl group or a lower alkoxy group; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independantly represent a hydrogen atom or a methyl group; and n is 0 or 1, and a herbicidal composition comprising as an active ingredient a herbicidally effective amount of compound represented by the following general formula: ##STR3## wherein A represents an alkylene group; B represents a nitrogen atom or CH; R represents a hydrogen atom, a lower alkyl group or a lower alkoxy group; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently represent a hydrogen atom or a methyl group; and n is 0 or 1, and
a herbicidally acceptable carrier or adjuvant.
It has already been known that a phenoxyphenylurea derivative has a herbicidal activity (Belgian Pat. No. 593743), and that a benzyloxyphenylurea derivative has a herbicidal activity (Japanese Patent Application Laid-Open (KOKAI) No. 53-44544 (1978)). It is also known that a phenethyloxyphenylurea derivative has a herbicidal activity (Japanese Patent Application Laid-Open (KOKAI) No. 53-108947 (1978)), and that a benzyloxypyridylurea and a phenethyloxypyridylurea derivative have a herbicidal activity (Japanese Patent Application Laid-Open (KOKAI) No. 55-122764 (1980)). Furthermore, it is known that a benzopyranyloxyphenylurea derivative has a herbicidal activity (PCT Patent Application Laid-Open No. WO87/00840). These compounds, however, are insufficient in the selectivity to crops or the strength of the herbicidal activity. Chemical substances (compounds) are very often changed in the presence or absence of the herbicidal activity, or the strength of the herbicidal activity, or in the selectivity of the herbicidal function by slightly changing the structure thereof. It is, therefore, difficult to forecast in advance the herbicidal activity or the selectivity of a new compound merely from the similarity of a chemical structure.
On the other hand, Japanese Patent Application Laid-Open (KOKAI) No. 57-158753 (1982) discloses compounds containing in the chemical structure a benzofuranyloxyphenylurea component as a bicyclooxyphenylurea having an insecticidal activity. These are, however, compounds having an insecticidal activity and no relationship to the above-described urea derivatives having a herbicidal activity is disclosed in Japanese Patent Application Laid-Open (KOKAI) No 57-158753 (1982).
Accordingly, the development of a substituted phenyl(or pyridyl)urea derivative exhibiting a high herbicidal effect in upland field and paddy field and having an excellent selectivity so as to do no practical harm to the crops has been in strong demand.
As a result of studies of the present inventors it has been found that a compound represented by the following general formula (I): ##STR4## wherein A represents an alkylene group; B represents a nitrogen atom or CH; R represents a hydrogen atom, a lower alkyl group or a lower alkoxy group; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independantly represent a hydrogen atom or a methyl group; and n is 0 or 1, is capable of controlling weeds in upland fields, such as lambsquarters (Chenopodium album), goosefoot (Chenopodium album var. centrorubrum), persicaria blumei gross (Polygonum blumei), ladysthumb (Polygonum persicaria), livid amaranth (Amaranthus lividus), common purselane (Portulaca oleracea), common chickweed (Stellaria media), dead-nettle (Lamium amplexicaule), large crabgrass (Digitaria sanguinalis), goosegrass (Eleusine indica), green foxtail (Setaria viridis), water foxtail (Alopecurus aequalis) and flat-sedge (Cyperus microiria) and weeds in paddy fields, such as false pimpernel (Lindernia procumbens), toothcup (Rotala indica), abunome (Dopatrium junceum), american waterwort (Elatine triandra), narrowleaf waterplantain (Alisma canaliculatum), barnyardgrass (Echinochloa crus-galli L. Beauv. var. crus-galli), umbrella plant (Cyperus difformis) and duck-tongue weed (Monochloria vaginalis) by the preemergence treatment or by the treatment during the growing stage, and in addition, do no practical harm to crop plants such as rice (Oryza sative), sunflower (Helianthus annuus), potato (Salanum tuberosum), wheat (Triticum aestivum), barley (Hordeum vulgare), sugar cane (Saccharum officinarum), and corn (Zea mays). On the basis of this finding, the present invention has been attained.